/*
 * Copyright (c) 2014, Oracle America, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 *  * Neither the name of Oracle nor the names of its contributors may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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 */
package com.hyr.jol.demo;

import org.openjdk.jol.datamodel.X86_32_DataModel;
import org.openjdk.jol.datamodel.X86_64_COOPS_DataModel;
import org.openjdk.jol.datamodel.X86_64_DataModel;
import org.openjdk.jol.info.ClassLayout;
import org.openjdk.jol.layouters.CurrentLayouter;
import org.openjdk.jol.layouters.HotSpotLayouter;
import org.openjdk.jol.layouters.Layouter;

/**
 * @author Aleksey Shipilev
 */
public class JOLSample_10_DataModels {

    /*
     * This example shows the differences between the data models.
     *
     * First layout is the actual VM layout, the remaining three
     * are simulations. You can see the reference sizes are different,
     * depending on VM bitness or mode. The header sizes are also
     * a bit different, see subsequent examples to understand why.
     */

    public static void main(String[] args) throws Exception {
        Layouter l;

        l = new CurrentLayouter();
        System.out.println("***** " + l);
        System.out.println(ClassLayout.parseClass(A.class, l).toPrintable());

        l = new HotSpotLayouter(new X86_32_DataModel());
        System.out.println("***** " + l);
        System.out.println(ClassLayout.parseClass(A.class, l).toPrintable());

        l = new HotSpotLayouter(new X86_64_DataModel());
        System.out.println("***** " + l);
        System.out.println(ClassLayout.parseClass(A.class, l).toPrintable());

        l = new HotSpotLayouter(new X86_64_COOPS_DataModel());
        System.out.println("***** " + l);
        System.out.println(ClassLayout.parseClass(A.class, l).toPrintable());
    }

    public static class A {
        Object a;
        Object b;
    }

}